When was the last time you noticed the local storm drain on your street? Many towns and cities in Wisconsin (and elsewhere) have storm drains along streets and within parking lots. These drains help remove storm water that might otherwise accumulate on these impervious surfaces and cause flooding. They almost always lead directly to local waterways, including streams, rivers and lakes without being treated to remove pollutants. Because storm water travels across streets, driveways, yards, or parking lots before entering a drain, it can accumulate contaminants such as oil, antifreeze, gasoline, soil, litter, pet waste, yard care chemicals, and yard waste.

If runoff from only one yard entered a local waterway through the storm drain, water quality might not be affected very much. However, when runoff from hundreds or thousands of yards or parking lots enters a waterway, the effect on water quality is more significant. Cumulative effects of polluted storm water from one community can cause beach closings, excessive aquatic plant growth, or degraded water quality which can affect fish and others aquatic organisms' survival.